Healthy weight and BMI

Healthy weight and BMI

There are a number of ways a person's weight can be assessed.

The most widely used method is Body mass index (BMI).

BMI is your weight in kilograms divided by your height in metres squared. There are many on line calculators such as safefood BMI calculator to work out your own BMI

  • A BMI under 18, is considered underweight
  • A BMI between 18 and 25, is considered a healthy weight
  • A BMI between 25 and 29, is considered overweight
  • A BMI is between 30 and 40, is considered obese
  • A BMI is over 40, is considered very obese (known as "morbidly obese")

The BMI calculation cannot take into account very muscular figures. Muscle can add extra weight, and this may give you an overweight or obese BMI, when you are not an unhealthy weight. For example, a heavyweight boxer would be classed as obese using the BMI, when he is in fact a healthy weight.  Though for most people, BMI remains an accurate method of assessing their weight.

Measure your waist.

Carrying excess fat around your waist area contributes more to serious health problems than carrying excess fat elsewhere in the body. There is an increased risk of metabolic complications such as insulin resistance, high cholesterol and abnormal fat distribution for men with a waist circumference ≥ 94cm (37 inches) and for women with a waist circumference ≥ 80cm (32 inches).

If you are concerned about your weight, please talk to our nurse in the student health centre.

To lower your risk

  • Reduce your consumption of high fat, salt and sugary foods
  • Increase your consumption of fruit and vegetables, as well as legumes, whole grains and nuts
  • Engage in regular physical activity
  • Make small, gradual changes to your eating and physical activity habits that you can keep up for life.
  • Eating meals at regular intervals throughout the day can help with any hunger pangs.
  • Drink plenty of water.
  • Be aware that “Fad diets” may promise you the world, but they tend not to work in the long-term. They’re normally too drastic for people to stick to for very long. Most of them are nutritionally unbalanced too.


To keep on track with a weight loss programme, try to:

  • Weigh yourself once a week
  • Keep a diary of your progress
  • Keep a food diary of what you eat each day – it’s a really handy way to focus on what you are eating and prevent you going back to old habits.

More information:

40 Weight-loss tips

Staying in Shape  

Problems associated with increased weight